More than 3/4 of fathers who are not married when their babies are born are involved with their newborns, but their involvement drops precipitously during early childhood. Based on the importance of fathers' involvement to children's development (Coley, in press; Duncan & Brooks-Gunn, 1997), this study investigates: What are the factors accounting for fathers' direct involvement with their infants? and How and why do many unmarried fathers become uninvolved with their children? The proposed study collects observational and self-report data from a quasi-representative sample of 55 unmarried African American parents when their babies are 6 weeks and then 1 year of age. Most studies of unwed father involvement focus on fathers' personal resources and financial support of children. The proposed study considers: (1) whether the quality of mother-father relationships facilitates fathers' instrumental involvement with their children, and (2) whether couple relationship quality accounts for individual differences in involvement over and above fathers' personal resources and financial support of children. The study also explores: (3) whether it is possible to identify promising and problematic styles of couple interaction from the perspective of father involvement; and (4) the dynamics of the link between couple relationships and father involvement, considering the direction of effects. The sample is part of a longitudinal study of unmarried parents, and future research will consider the role of early mother-father relationships and fathers' involvement in predicting children's adaptation as preschoolers.